In recent years, an electric vehicle, a hybrid vehicle, a fuel cell vehicle and the like have received attention as an environmentally-friendly vehicle. On these vehicles, a motor that generates driving force for traveling as well as a power storage device that stores electric power supplied to the motor are mounted. The hybrid vehicle further has an internal combustion engine mounted thereon as a power source, together with the motor. The fuel cell vehicle has a fuel cell mounted thereon as a direct current (DC) power supply for driving the vehicle. Among these vehicles, a vehicle is known in which a vehicle-mounted power storage device for driving the vehicle can be charged from a power supply in ordinary households. For example, a power supply outlet provided at home is connected to a charging port provided at the vehicle by using a charging cable, so that electric power is supplied from the power supply in the ordinary households to the power storage device. It is noted that the vehicle in which the vehicle-mounted power storage device can be charged from the power supply external to the vehicle as described above will also be referred to as “plug-in vehicle” hereinafter. For example, Japanese Patent Laying-Open No. 2000-270484 (Patent Document 1) discloses a technique of detecting an abnormality such as a break or a power failure of a commercial power supply after charging starts in the foregoing plug-in vehicle.
An abnormality detecting apparatus disclosed in Japanese Patent Laying-Open No. 2000-270484 includes: a motor; a battery; a converting unit connected between the motor and the battery, for converting an alternating current from the commercial power supply to a direct current via the motor in accordance with a switching signal and supplying the direct current to the battery; a voltage phase detecting unit connected between the motor and the commercial power supply, for determining zero cross on/off of a commercial power supply voltage and detecting a voltage phase of the commercial power supply voltage; a first current detecting unit for detecting the alternating current flowing through a coil of the motor; a second current detecting unit for detecting the direct current supplied from the converting unit to the battery; a command value generating unit for generating an alternating current command value based on a command value for charging, the result of the detection by the second current detecting unit, and the voltage phase; a switching signal generating unit for generating a switching signal based on the alternating current command value and the result of the detection by the first current detecting unit; and an abnormality detecting unit for detecting an abnormality based on the alternating current command value and the result of the detection by the first current detecting unit.
According to the abnormality detecting apparatus disclosed in Japanese Patent Laying-Open No. 2000-270484, the alternating current from the commercial power supply is converted to the direct current via the motor in accordance with the switching signal, and the direct current is supplied to the battery. Then, the zero cross on/off of the commercial power supply voltage of the commercial power supply is determined, the voltage phase of the commercial power supply voltage is detected, and the alternating current flowing through the coil of the motor as well as the direct current supplied to the battery are detected. In addition, the alternating current command value is generated based on the command value for charging, the result of the detection of the direct current, and the voltage phase. The switching signal is generated based on the alternating current command value and the result of the detection of the alternating current. Moreover, the abnormality is detected based on the alternating current command value and the result of the detection of the alternating current. Accordingly, the abnormality that occurs at a charging control apparatus after charging starts can be detected. In addition, since it is not required to place a new special sensor for detecting the abnormality, the cost of the abnormality detecting apparatus can be reduced.    Patent Document 1: Japanese Patent Laying-Open No. 2000-270484